Simplex Derailleur Overhaul

I was rebuilding an old Peugeot UO-8 and noticed the rear derailleur didn't have much tension on it. It's incredibly easy to take apart, so why not try to make it work better? I believe this one is a Simplex Prestige:

The first thing to do is unscrew the 14mm nut behind the mounting claw while holding the allen bolt steady on the other side:

Next you remove the stop screw for the pulley cage:

Then you can let the cage unwind. Now unscrew the other allen bolt holding the pulley cage to the derailleur:

Slide the allen bolts out. You can see the springs inside, which you can grease now:

As for the pulley cage, unscrew the 2 nuts holding the cage together:

With the pulleys out, you can clean and oil the bushings that they spin on:

All taken apart:

Reassembly is the reverse of removal, except for that 14mm nut behind the mounting claw. You should screw it back on loosely, but wait until you install the derailleur on the bike before you tighten it. Once installed, wind the derailleur clockwise against the spring tension, then hold it steady while tightening that nut. You need to do it this way to give the spring some tension, otherwise the top pulley will touch the sprockets while you ride.